Re: [PATCH] block: introduce content activity based ioprio

[Zhaoyang Huang]

On Tue, Jan 23, 2024 at 9:06 PM Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote:
>
> On Tue, Jan 23, 2024 at 05:33:52PM +0800, zhaoyang.huang wrote:
> >  #define ALLOC_CACHE_MAX              256
> > @@ -1069,12 +1070,21 @@ EXPORT_SYMBOL_GPL(bio_add_zone_append_page);
> >  void __bio_add_page(struct bio *bio, struct page *page,
> >               unsigned int len, unsigned int off)
> >  {
> > +     int class, level, hint, activity;
> > +
> > +     class = IOPRIO_PRIO_CLASS(bio->bi_ioprio);
> > +     level = IOPRIO_PRIO_LEVEL(bio->bi_ioprio);
> > +     hint = IOPRIO_PRIO_HINT(bio->bi_ioprio);
> > +     activity = IOPRIO_PRIO_ACTIVITY(bio->bi_ioprio);
> > +
> >       WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED));
> >       WARN_ON_ONCE(bio_full(bio, len));
> >
> >       bvec_set_page(&bio->bi_io_vec[bio->bi_vcnt], page, len, off);
> >       bio->bi_iter.bi_size += len;
> >       bio->bi_vcnt++;
> > +     activity += (bio->bi_vcnt <= IOPRIO_NR_ACTIVITY && PageWorkingset(page)) ? 1 : 0;
>
> The block layer must not look at page bits.  I've fixed all this crap
> with a lot of work and we're not going to re-add it for another qute
> hack.  The place to figure out any kind of I/O priority is the file
> system (preferably using generic helpers).
ok, will use helper function in next version
>